The present invention relates to interactive environment systems such as immersive games and virtual reality or shared (multi-user) virtual environment systems which provide the user or users with a view of a virtual world within which the users computer-generated virtual presence appears and may interact with other such user virtual presences as well as, optionally, features of the environment itself. In particular, the present invention relates to such systems having means for controllably varying the viewpoint from which the image of the environment (as presented to a user) is rendered, a feature referred to herein as "virtual camera" control.
A description of a system providing a virtual environment (or cyberspace) accessible by remote users is given in European patent application EP-A-0 697 613 (Sony Corp.). The system described includes a server providing a virtual reality space, and user terminals connected to the server via a high-speed communications network (using optical fibres or the like). In operation, the server maintains a number of virtual environments and supports many differing terminal types by the use of conversion objects between information objects and user objects: the conversion objects provide individually tailored translation for communications back and forth between each type of terminal and each configuration of virtual environment supported.
At each user terminal, the user is presented with a two-dimensional view of the three-dimensional virtual environment from their own particular viewpoint location within the three-dimensional environment, with computer-generated representations of any other users who may at that time be within the same area of the virtual environment as the viewing user. Rather than generating a representation of a whole or part of the viewing user in the image seen by that user, the system of EP-A-0 697 613 takes the first-person view (i.e. the image is that which would be seen through the "eyes" of the users computer generated character) but provides a simple arrow-shaped cursor which the user may utilise to indicate or select items from within the virtual environment by up/down/left/right movements of the cursor in the presented two-dimensional image of the environment or, by clicking on the virtual character of a further user, to initiate a conversation or other interaction between two users. This technique is used in EP-A-0 697 613 as an improvement to a described prior art system in which the user is represented by a rendered character always appearing in the centre of the image presented to the user, such that the user takes a third-person view of their representation within the virtual environment.
Although rendering from the first-person point of view enhances a users feeling of immersion within the virtual environment, it can prove less than satisfactory when it comes to interacting with the virtual representations of other users where the third-person point of view provides the user with more information in the way of context for the interaction. Being able to select the viewpoint (virtual camera position) relative to your own representation would be an asset but the requirement to do so could become a distraction over time.